001 /* 002 * Licensed to the Apache Software Foundation (ASF) under one 003 * or more contributor license agreements. See the NOTICE file 004 * distributed with this work for additional information 005 * regarding copyright ownership. The ASF licenses this file 006 * to you under the Apache License, Version 2.0 (the 007 * "License"); you may not use this file except in compliance 008 * with the License. You may obtain a copy of the License at 009 * 010 * http://www.apache.org/licenses/LICENSE-2.0 011 * 012 * Unless required by applicable law or agreed to in writing, 013 * software distributed under the License is distributed on an 014 * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY 015 * KIND, either express or implied. See the License for the 016 * specific language governing permissions and limitations 017 * under the License. 018 */ 019 020 package org.apache.geronimo.javamail.transport.nntp; 021 022 import java.io.IOException; 023 import java.io.InputStream; 024 import java.io.UnsupportedEncodingException; 025 import java.util.List; 026 027 /** 028 * @version $Rev: 437941 $ $Date: 2006-08-28 23:56:02 -0400 (Mon, 28 Aug 2006) $ 029 */ 030 public class StringListInputStream extends InputStream { 031 // the list of lines we're reading from 032 protected List lines; 033 034 // the next line to process. 035 protected int nextLine = 0; 036 037 // current buffer of bytes to read from 038 byte[] buffer; 039 040 // current offset within the buffer; 041 int offset; 042 043 // indicator that we've left off at a split between the CR and LF of a line 044 // break. 045 boolean atLineBreak = false; 046 047 public StringListInputStream(List lines) throws IOException { 048 this.lines = lines; 049 nextLine = 0; 050 buffer = null; 051 offset = 0; 052 atLineBreak = false; 053 054 // if we have at least one line in the list, get the bytes now. 055 if (lines.size() > 0) { 056 nextBuffer(); 057 } 058 } 059 060 /** 061 * Just override the single byte read version, which handles all of the 062 * lineend markers correctly. 063 * 064 * @return The next byte from the stream or -1 if we've hit the EOF. 065 */ 066 public int read() throws IOException { 067 // leave off at the split between a line? 068 if (atLineBreak) { 069 // flip this off and return the second line end character. Also step 070 // to the next line. 071 atLineBreak = false; 072 nextBuffer(); 073 return '\n'; 074 } 075 // gone past the end? Got an EOF 076 if (buffer == null) { 077 return -1; 078 } 079 080 // reach the end of the line? 081 if (offset >= buffer.length) { 082 // we're now working on a virtual linebreak 083 atLineBreak = true; 084 return '\r'; 085 } 086 // just return the next byte 087 return buffer[offset++]; 088 089 } 090 091 /** 092 * Step to the next buffer of string data. 093 * 094 * @exception IOException 095 */ 096 protected void nextBuffer() throws IOException { 097 // give an eof check. 098 if (nextLine >= lines.size()) { 099 buffer = null; 100 } else { 101 try { 102 String next = (String) lines.get(nextLine++); 103 buffer = next.getBytes("US-ASCII"); 104 105 } catch (UnsupportedEncodingException e) { 106 throw new IOException("Invalid string encoding"); 107 } 108 } 109 110 offset = 0; 111 } 112 }